This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Post infarction, left ventricular remodeling is responsible for almost a quarter of heart failure instances and it is believed that infarct expansion and dilatation is an important factor for initiating and sustaining this process. Understanding the pathophysiology that occurs after an infarction is necessary for intervention and limiting infarct expansion and ventricular remodeling. Given cost and availability constraints, surface endocardiograms and serum chemistries are the most common methods to diagnose MI and infarct expansion, although delayed contrast enhanced (DCE-MRI) is also used. The purpose of this project is to develop a rapid pulse sequence for cardiac T1[unreadable] imaging by KWIC reconstruction and to measure 1H relaxation times in vivo. We hypothesize that there are measurable transverse relaxation time changes during the cardiac cycle, which may be used as a surrogate measure of cardiac stress.